In a statement to USA TODAY, the Feldstein family said Feldstein called 911 after experiencing shortness of breath. He had gone into cardiac arrest by the time paramedics arrived and died a short time later.

“It was a tragedy foisted upon us and far and away one of the saddest moments of our lives, and personally of mine,” he told Variety in the cover story for the latest issue. “This is a kid I’ve known since we were in diapers. He was one of the most important people in my life from a very early age.”

The “Voice” coach said he thinks of Feldstein “every day.”

“It will always be something that’s missing in my life. I break down; I cry. We built this together, and it will never be complete without him,” he adds. “But at the same time, we know he wants us to keep trucking.”

Feldstein was the founder and chief executive of Career Artist Management and had managed Maroon 5 since its inception 15 years ago. His company also counts Miguel, The B-52s, Elle King and Rick Springfield among its clients.

Levine tapped Feldstein’s mentor and business partner, Irving Azoff, to co-manage Maroon 5 along with Adam “Ash” Harrison and himself, according to Variety. The father of two said it was difficult to move forward without Feldstein.

“It was brutal. When that all went down, I remember having to dig deep and say to myself, ‘Am I just going to let this fall apart, or am I going to try and hold this thing together?’ ” he said. “I thought to myself, ‘How do I make this all work again?’ I know that he would have wanted me to hold it together.”

Feldstein could possibly have helped guide Maroon 5 through the backlash of their controversial decision to reportedly perform during the upcoming Super Bowl halftime show. (More than 47,000 people, and celebrities such as Rihanna and Amy Schumer, have called for the band to bow out in support of former NFL player Colin Kaepernick.)

When Variety asked Levine about taking part in the Super Bowl LIII festivities, he responded: “I’m still formulating a lot of things.”